Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-16T03:26:37.683Z Has data issue: false hasContentIssue false
  • English
  • Français

Enhanced tunable performance of high Q-factor BaxSr1−xTiO3 film bulk acoustic wave resonators

Published online by Cambridge University Press:  15 April 2013

Andrei Vorobiev  and
Spartak Gevorgian
Andrei Vorobiev*
Affiliation:
Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412-96 Gothenburg, Sweden
Spartak Gevorgian
Affiliation:
Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412-96 Gothenburg, Sweden
*
Corresponding author: A. Vorobiev Email: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Emerging intrinsically tunable film bulk acoustic wave(BAW) resonators allow the development of new generation reconfigurable and agile microwave circuits. In this paper, we demonstrate the enhancement of tunable performance of the high Q-factor BaxSr1−xTiO3 BAW – solidly mounted resonators (BAW–SMR) by varying Ba concentration. The Ba0.5Sr0.5TiO3 BAW–SMR reveal tunability of series resonance frequency up to 2.4%, electromechanical coupling coefficient up to 7.5% and rather high Q-factor, up to 250 at 5.3 GHz. Correlations between the measured electroacoustic parameters are analyzed using the theory of dc field-induced piezoelectric effect in paraelectric phase ferroelectrics. Higher coupling coefficient and tunability of resonance frequency of the Ba0.5Sr0.5TiO3 BAW–SMR are associated with higher tunability of permittivity. Strong anisotropy in field-induced piezoelectric effect is predicted with highest coupling coefficient in (001) direction of the BaxSr1−xTiO3 films. It is also shown that the tunability of series resonance frequency of Ba0.5Sr0.5TiO3 BAW–SMR is limited by relatively high and negative nonlinear electrostriction coefficient which is found to be m ≈ −4·1010 m/F. The BAW–SMR Q-factor is limited significantly by extrinsic acoustic loss associated with wave scattering at reflection from relatively rough top interface. The results of analysis show possible ways of further improvement of the performance of tunable BAW–SMR.

Keywords

New and emerging technologies and materialsPassive components and circuits
Type
Research Papers
Information
International Journal of Microwave and Wireless Technologies , Volume 5 , Special Issue 3: European Microwave Week 2012 , June 2013 , pp. 361 - 369
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Noeth, A.; Yamada, T.; Muralt, P.; Tagantsev, A.K.; Setter, N.: Tunable thin film bulk acoustic wave resonator based on BaxSr1−xTiO3 thin film. IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 57 (2010), 379–385.CrossRefGoogle ScholarPubMed
[2]Sis, S.A.; Lee, V.; Phillips, J.D.; Mortazawi, A.: Intrinsically switchable thin film ferroelectric resonators. IEEE MTT-S Int. Microw. Symp. Dig., 1 (2012), 1–3.Google Scholar
[3]Saddik, G.N.; Son, J.; Stemmer, S.; York, R.A.: Improvement of barium strontium titanate solidly mounted resonator quality factor by reduction in electrode surface roughness. J. Appl. Phys., 109 (2011), 091606-1-3.Google Scholar
[4]Volatier, A.; Defay, E.; Aid, M.; Nhari, A.; Ancey, P.; Dubus, B.: Switchable and tunable strontium titanate electrostrictive bulk acoustic wave resonator integrated with a Bragg mirror. Appl. Phys. Lett., 92 (2008), 032906-1-3.Google Scholar
[5]Ivira, B.; Reinhardt, A.; Defaÿ, E.; Aid, M.: Integration of electrostrictive Ba0.7Sr0.3TiO3 thin films into bulk acoustic wave resonator for RF-frequency tuning under DC bias. IEEE Int. Freq. Contr. Sym. Dig., 1 (2008), 254–258.Google Scholar
[6]Berge, J.; Gevorgian, S.: Tunable bulk acoustic wave resonators based on Ba0.25Sr0.75TiO3 thin films and a HfO2/SiO2 bragg reflector. IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 58 (2011), 2768–2771.Google Scholar
[7]Vorobiev, A.; Gevorgian, S.; Löffler, M.; Olsson, E.: Correlations between microstructure and Q-factor of tunable thin film bulk acoustic wave resonators. J. Appl. Phys., 110 (2011), 054102–11.Google Scholar
[8]Vorobiev, A.; Gevorgian, S.: Tunable thin film bulk acoustic wave resonators with improved Q-factor. Appl. Phys. Lett., 96 (2010), 212904–3.Google Scholar
[9]Hashimoto, K.-Y.: RF Bulk Acoustic Wave Filters for Communications, Artech House, Norwood, MA, 2009.Google Scholar
[10]Vorobiev, A.; Berge, J.; Gevorgian, S.; Löffler, M.; Olsson, E.: Effect of interface roughness on acoustic loss in tunable thin film bulk acoustic wave resonators. J. Appl. Phys., 110 (2011), 024116–4.Google Scholar
[11]Nam, K.; Park, Y.; Ha, B.; Shim, D.; Song, I.: Piezoelectric properties of aluminium nitride for thin film bulk acoustic wave resonator. J. Korean Phys. Soc., 47 (2005), S309–S312.Google Scholar
[12]Noeth, A.; Yamada, T.; Sherman, V.O.; Muralt, P.; Tagantsev, A.K.; Setter, N.: Tuning of direct current bias-induced resonances in micromachined Ba0.3Sr0.7TiO3 thin-film capacitors. J. Appl. Phys., 102 (2007), 114110-1-7.Google Scholar
[13]Tagantsev, A.K.; Sherman, V.O.; Astafiev, K.F.; Venkatesh, J.; Setter, N.: Ferroelectric materials for microwave tunable applications. J. Electroceram., 11 (2003), 5–66.Google Scholar
[14]Noeth, A.; Yamada, T.; Tagantsev, A.K.; Setter, N.: Electrical tuning of dc bias induced acoustic resonances in paraelectric thin films. J. Appl. Phys., 104 (2008), 094102-1-10.Google Scholar
[15]Noeth, A.; Yamada, T.; Sherman, V.O.; Muralt, P.; Tagantsev, A.K.; Setter, N.: DC bias-dependent shift of the resonance frequencies in BST thin film membranes. IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 54 (2007), 2487–2492.CrossRefGoogle ScholarPubMed
[16]Vorobiev, A.; Rundqvist, P.; Khamchane, K.; Gevorgian, S.: Microwave loss mechanisms in Ba0.25Sr0.75TiO3 thin film varactors. J. Appl. Phys., 96 (2004), 4642–4649.Google Scholar
[17]Alekseev, S.G.; Mansfel'd, G.D.; Polzikova, N.I.; Kotelyanskii, I.M.: Attenuation and trapping of acoustic energy in composite microwave resonators based on YAG single crystals. Acoust. Phys., 53 (2007), 465–470.Google Scholar
[18]Löffler, M.; Vorobiev, A.; Zeng, L.; Gevorgian, S.; Olsson, E.: Adhesion layer-bottom electrode interaction during BaxSr1-xTiO3 growth as a limiting factor for device performance. J. Appl. Phys., 111 (2012), 124514-1-6.CrossRefGoogle Scholar